The present invention relates to a solenoid operated valve, and particularly, to a solenoid operated valve preferably used in a variable capacity compressor.

One example of a priorly known solenoid operated valve being used in a variable capacity compressor is disclosed in Japanese Laid-Open Patent Publication No. S63-147978, and FIG. 13 is a cross-sectional view showing the structural outline of the prior art valve mounted to a compressor.
As shown in FIG. 13, a solenoid operated valve 10 is sandwiched between side plates 15 and 16 of the compressor, and a body 17 of the valve 10 is mounted through o-rings 13 and 14 to a plate 15 of the compressor. A pressure induction hole 18 and a pressure discharge hole 19 are formed in the body 17. A valve member 26 for opening and closing the pressure induction hole 18 and the pressure discharge hole 19 are provided in the valve 10, and the valve member 26 is crimped onto the end of a plunger 20. The plunger 20 is slidably inserted into a plunger pipe 23 formed in the interior of an electromagnetic coil 21. A suction element 24 is positioned so as to oppose the plunger 20. The suction element 24 is also stored in the interior of the electromagnetic coil 21, and fit to the plunger pipe 23.
A spring 25 is mounted between the suction element 24 and the plunger 20. The spring 25 biases the plunger 20 away from the suction element 24. In other words, the force of the spring 25 pushes the valve member 26 in the direction to close the pressure discharge hole 19. A steel housing 27 is mounted to. the exterior of the electromagnetic coil 21. A steel cap 28 is crimped onto the upper end of the housing 27, and the cap 28 is fit into and fixed to the side plate 16.
One end of a lead wire of the electromagnetic coil 21 is electrically connected to a connector 29. The other end of the connector is not shown. FIG. 13 shows the state where the power is not supplied to the electromagnetic coil 21, and the valve is closed.
According to the solenoid operated valve of prior art, the body and the plunger pipe are formed as separate units. Therefore, it was difficult to obtain coaxiality between the body and the plunger, which leads to problems such as valve leakage or operation failure due to deflection of the valve member.
Further, since the body and the plunger pipe of the conventional solenoid operated valve are separate, the manufacturing cost of the valve is relatively expensive.
Moreover, since the body and the plunger pipe are formed separately and there is a need to assemble the separate members, dispersion is likely to occur between the lift of the plunger and the lift of the valve member. This leads to unstabilized suction power and unstabilized open valve flow, which results in the lack of capability of the variable capacity compressor.
The present invention aims at solving the above problems. The object of the present invention is to utilize a pipe sleeve with a bottom formed by deep drawing, which constitutes the body and the plunger pipe integrally. Thereby, a solenoid operated valve having improved reliability and performance, and with no valve leakage or motion troubles may be provided.
Another object of the present invention is to provide a solenoid operated valve having accurate suction force and flow rate of the plunger, which leads to stabilized variability of the variable capacity compressor.
Yet another object of the present invention is to provide a valve with improved magnetic properties and a reduced number of members to be assembled.
In order to achieve the above objects, the present invention provides a solenoid operated valve in which a suction element is attracted by an electromagnetic coil, comprising a body and a plunger pipe being integrally formed as a pipe sleeve to which said suction element is inserted and fixed, and a plunger slidably mounted within said pipe sleeve and including a valve member, wherein said pipe sleeve is formed by deep drawing to include a bottom portion, and a valve opening is equipped to said bottom portion.
Further, the embodiment of the present solenoid operated valve includes forming a step portion to the pipe sleeve, and to press-fit a filter to the pipe sleeve which stops at the step portion, thereby being fixed to the pipe sleeve.
Moreover, according to another embodiment of the present solenoid operated valve, a filter is mounted to the flow-in opening of the pipe sleeve.
According to the valve of the present invention, the plunger pipe and the body are formed integrally as a deep-drawn pipe sleeve with a bottom, which is different from the prior art valve in which the plunger pipe and the body are formed as separate members. According to the structure of the present invention, the coaxiality of the valve will be improved, and deflection of the valve member equipped in the plunger may be prevented, thereby improving the performances and reliability of the valve.
Even further, since the plunger pipe and the body are integrally formed as one unit, the number of members to be assembled is reduced, and the dispersion of the lift of the valve member and the plunger during assembly may be reduced, which leads to obtaining an accurate flow rate of the valve.
Moreover, since the pipe sleeve is formed as a deep-drawn integrated pipe with a bottom, the filter may be accurately mounted to the pipe sleeve.